Process of manufacture of chemical or sulfite wood-pulp.



. r of c These chips are cut UhTITED surge PATENT OFFICE.

' Bonner ROE, .13., or NIAGARA, WISCONSIN.

Pnocs ss oF MANUFACTURE OF CHEMICAL on suL irs are. 833,750.,

Specification of Letters lfatent, Application tiled If'cbrury 1, late. emu s 21am.

ween-Puts.

latented Oct. so, nice; {i

ITo alZ whom it mwy concern.-

lilo it known that L Bonnnr Ron, Jr.,, a oitlzen of the United States, residi at Niagare, in the county of Marinette an d 5 Wisconsin, have invented certain new and useful Improvementsin; Processes ofManufacture ofChelnical or Sulfite Wood-Pulp, of

p which the followin? is a specification.

invention re ates to the recess of arti- 1o fic y dying wood-ohips use in the manufacture o wood-pulp by the chemical or sul- "fite process aud t consists of the novel com-' bination ofthe several process steps hereinafter described, and specifically set forth in theclaimsv w In the manufacture of chemical or sulfite pul from wood the wood is used in the form fromlogs' (or occasionally from slabs and sawmill waste) :0 by'means of a heavy circular revolvx1ng disk, upon the face of which are set several knives bolted inposition and at such an Is that when a log or piece of wood is pushed against the revolving disk a chip about threeuarters of an inch in 16 th 18 out off by eac knife in passing, which'c p is so out o piece of wood, but in a direction diagonal to the diameter. This action of the revolving 3o knives is'similar in its results to the action 0 V a hatchet... These chips have heretofore not been dried artificialliyg nor is it necessary that they should be that much better results are ob'tainedby the artificial drying of the chips, as I will ently explain, before they are intro uced into the est apparatus and' there subjected to c emica action.

In the cuttin scribed, a consi erable portion of the rod'uct of the operationis waste, consist 0 knots dirt, and other refusc' matter, e 00 chips have sometimes been separated om this-waste or refuse by throwing the whole into atank of water,'mth the result that the cod chips float and theknots andother undesired matter sink. Some ofthegoodlchips, however, may be or become water-logged, and these will sink also. Such'chips have usuallybeen thrown away with the waste; but as they amount sometimes to as much as five per cent. of the entire product it is nc v thought desirable to recover the cod chips so lost. iThis is accomplished b 'ng m a suitable apparatus the whole 0 sue waste product,

State of the digesting apparatus, in which t lire if not diametrically of, the log orv q ed; but I have found res-- ture of sulfite pulp when the chips'are first of wood-chips, as above dew is more whereupon it is all thrown into the tank of water a second time, with the result that'the good chips, which before were water-lo god, a and consequently sank, now float an fare. takenput while theknots andother heavy 6o undesirable substances again sink and become waste. This floating or "and floating operation, however, is who y' or the purpose of ssparatipf out the chips, which are propeffor the p manufacture, and in every nstance the ch ps, which go the d gesting a paratlis'fonchemical treatment, are those w ch are moreonlesswet j The chips'are usually stored taken when required in su table quantities to pubjec ed ,to the action of an a'cid or c em.- ioals. This ,acid is usually the bisulli hme and magnesia, which,.asis well kn in theart, is made bi burning ,-a1itl"7'5 g the gas throng "a milk of lime,'. (and xnagnesia mixed, five hundred pounds'of hnie to five thousand gallons of water being a eonunondproportion. When the h1g0! has clearedan isfoundtobeofsuflicients ength, it is stored in tanks and is drawn off as reuirecl. The operation in the digester is r comm'only'called "cooking* and consists in submergllrig in the digester ,a pro or quantity of c pain a roper quanti y this acid and" boiling tun er sevent -five to eighty poundspressure with the iii of steam.

I have found by ent thatmuch better results are obtained in the'manuiacgo artificially dried and thstwet wood made into chi s which are artificiallfildried u do c ps ,duces a otter ualit ofp'ulpt 'oh are mad I e from dry seasoned wood, A larger quantity of chi s can be ot into the eirbe'ing ess bulky) digester (on account of than ofeither wet chips or ,chips from seasoned wood. The 801d, penetrates much more readily the artificiallydried chips the others named, and th refore the cooking roo There is an actual old of fiber from a given quantity creased the use of o of woe because b chips, as above descr; d,- the cooking 18 necessarily prolonged to the point where e mm5 terior portions of the chips are cooked fsufiicientl'y, and in doing this the surfaces of the chipsare subjected .to overcoolnng, because the cooking commences lit and near the surface before the acid has penetrated to the no center, and conseguently some ofthe fibers are dissolved an destroyed by excessive acid notion, '(thus causing loss,) and in en-' other portion the fibers are reduced in length and streigrth, (thus causing a. poor uelity of pulpd y In process the time cooking materiall s ortened, so enabling a larger output per iem. The moisture in the chlps is completely extracted, while in seasoned wood under the processes heretofore used twenty-five per cent. to thirty per cent. of the moistureis retained. There are no disadvuntegesin the use of my said process but in every respect there are great advantages.

I do notwish to be confined to any perticuler method-otdryin the chipsl Any urtificiel method will yie d valuebie results and embody the principle of my invention. I

may employ cool air or gases in large vol-- umes to carry away the moisture of the chi s or warm air or gases m'lesser-volumes for t e same purpose, or the moisturemay be' ex- 7 'trected hycentrifugelly-acting devices or witheome of the eeid with which the era to t be cooked or digested g but such prehminery or partial mifiehl' dryinf of theichips 1 wood-chi s.

2. In t is manufacture of chemical or sulfite Woocl-pulp, the im roved process herein described, consisting 0 the cutting of chips from wet wood, then artificially drying said chips, end then cookin said chips in e digester by means of ac: and under steampressure.

3. In the manufacture of chemical or sulfite wood-pul the improved process herein described of t 1e cutting of'chips fromunseesoned 'wood then artificially drying said chips, and then cooking said chips in a di gester hyihean's. of, acid and under steampressure.

4. In the manufacture of chemical or sulfite wood-pulp, the process of cutting chips, then extractin the moisture of said chigs, and thencookmg said chips in a (ligester y means of acid under steam-pressure.

I31 testimony whereof I efiix' my signature in presence of two witnesses.

ROBERT ROE; In. 'Witnesses'z CHAS. A. Sommns, Y ALBERT W. Tomas. 

